The invention relates generally to telecommunication systems, and more particularly to the use of debit cards in a system that does not require a centralized server for customer accounts.
A debit card or prepaid calling system allows callers to charge telephone call costs against a prepaid amount that has been deposited by the callers. Prepaid calling systems can be used in both wireline and wireless telecommunications systems. Typically, users deposit a prepaid amount in an account that has been established with a debit card calling service provider. Debit card calls that are made through the service provider""s system are charged against the user""s prepaid account balance. Service providers can determine the cost for a particular debit card call in a number of ways. For example, users may be charged at a flat per-minute rate which essentially gives users a set number of calling minutes based upon the amount of money in the prepaid account. In a flat rate system, all calls to any telecommunications destination are billed at the same rate without regard to distance. Also, service providers can set a variable billing rate in which rates are based upon the distance of the calling destination.
The users"" prepaid amounts are usually stored in a single centralized server or database. This central unit holds account information for every prepaid customer in the system. The user account records typically comprise such information as a current prepaid balance, an account number, a personal identification number (PIN) or password, and the user""s billing rate plan.
Callers can access the debit card calling system in a variety of ways. In some systems users must first call a dedicated routing number. This number routes them to the centralized server which then prompts the callers to provide additional information such as an account number, PIN or destination telephone number. In other systems, users directly dial a destination telephone number and the call charges are billed to a prepaid account that is associated with the device from which the call originates, such as a particular business or residential telephone or a wireless device.
The prior art prepaid calling systems either route all calls through a central server or use a central server for maintaining customer account records. The use of a central database creates problems in the prior art systems by providing a single point of failure. If the central database or server fails, then the entire network will fail since customer accounts can no longer be accessed to verify accounts or to debit account balances.
Another problem with prior art debit card calling systems is the call volume. Since all of the prepaid calls must go through the central server, or at least access the central server for the customer records, this creates a heavy demand on the central database. The high demand levels create the need for a very fast database server at the central location that can service all of the calls in the system.
The problems of the prior art debit card calling systems are solved by a system and method in which database servers and call processors are distributed to a number of remote locations. Instead of routing all of the users through a central system, in the present invention the prepaid callers are serviced by local call processors that are coupled to the remote servers. The use of local call processors at the remote locations reduces the call volume that is handled by each call processor and server. As a result, the demand levels on each call processor and server are reduced. Thus, the present system works faster and more efficiently.
Each remote server in this decentralized system, is linked via a wide area network (WAN) or other data communications network which allows the servers to exchange user account information. The present invention maintains a single database record for each user, however the account records do not have to be stored on a central server. Instead, user account records are distributed among the various remote servers so that each customer""s record is resident on the server that serves the customer""s home location or on the server that was last used by the caller.
Debit card calls are routed through the local call processor, which exchanges data with the local server. The call processor and the server verify that the user has a valid prepaid account and begin calculating charges for the call. The local server will either have the user""s record resident in a local database or it will obtain the record from another server via the WAN. The call processor continues to route the call while the server obtains and verifies the user""s account balance. If the user""s balance is zero or below a minimum amount, then the call will be terminated. Otherwise, if there is a sufficient account balance the call processor and server monitor the running charges for the call and deduct the costs from the account balance.
Prepaid calls are terminated by the parties when they hang up or by the call processor when the debit card balance falls below a minimum amount. Using the account balance and the billing rate for a particular call, the call processor and server can calculate how much connection time remains before the account balance falls to the minimum level. The call processor may provide the customer with periodic time remaining warnings when the account balance approaches a minimum amount.
After the connection is disconnected the user""s account record will be updated on the local server. The account remains on the local server until it is required for a future call. In most cases the debit card customer will call from the same area, so his or her future calls will be routed through the same home location call processor. As a result, the customer""s record will usually be readily available. However, if the customer travels to another area or if more than one person uses the same account, then a future prepaid call may be routed through a second call processor. In this situation, a second server will require the prepaid caller""s record in order to handle the call. Accordingly, the second server will request access to the customer""s account from home server or from whichever server currently holds the account. As long as the account is not in use, the home server will provide the account record to the second server.
In one embodiment, a coordinating server is used in the debit card calling system to track the location of each user record. Whenever a record is transferred from one server to another, the record location is updated in the coordinating server. In another embodiment, if there are few remote servers, instead of using a coordinating server, each remote server can poll the other servers to determine the location of a particular customer record.
By only allowing one copy of a customer record to exist, the present system can prevent fraud by limiting access to customer accounts to only one server at a time if desired. Thus, only one caller at a time may use each account. This prevents two or more callers in separate areas from making charges against the same account balance simultaneously. If a caller attempts to use a prepaid account that is already in use, then the system may terminate the second caller""s connection.
WAN traffic is also reduced in the present system since most debit card users will usually call from one area. As a result the user""s record will always be available on the local or last-used server. User account transfers on the WAN will have to be made only when the customer changes locations between calls. In prior art systems, the customer""s record must be obtained via the WAN from a central location for each call.
It is a feature of the present invention to reduce network traffic in a debit card calling system by storing customer accounts in a server at a home or a last-used location. Other servers in a second location can obtain a particular customer record via the WAN when the customer initiates a call from the second area.
It is an another feature of the present invention to reduce delays in connecting prepaid callers to called destinations, by allowing debit card calls to be routed concurrently with verification of the prepaid user""s account information. In the event that the present system determines that a prepaid account has a zero balance or insufficient funds for a particular call, the system is capable of terminating a completed calling connection.
It is a further feature of the present invention to reduce telecommunications system failures, crashes and down time by eliminating the single point of failure problems of the prior art. By assuming that callers will typically make a series of calls from one location, network traffic in the system is reduced by storing user call records at the location most likely to be used by each debit card caller for a future call.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.